From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Jim Quinlan <jim2101024@gmail.com>,
linux-pci@vger.kernel.org,
Nicolas Saenz Julienne <nsaenz@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Cyril Brulebois <kibi@debian.org>,
Phil Elwell <phil@raspberrypi.com>,
bcm-kernel-feedback-list@broadcom.com,
james.quinlan@broadcom.com
Cc: "Florian Fainelli" <f.fainelli@gmail.com>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
"moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-rpi-kernel@lists.infradead.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/3] dt-bindings: PCI: brcmstb: Add two optional props
Date: Wed, 12 Apr 2023 10:09:05 +0200 [thread overview]
Message-ID: <5a28e520-63e4-dbcf-5b3e-e5097f02dea2@linaro.org> (raw)
In-Reply-To: <20230411165919.23955-2-jim2101024@gmail.com>
On 11/04/2023 18:59, Jim Quinlan wrote:
> Regarding "brcm,enable-l1ss":
>
> The Broadcom STB/CM PCIe HW -- a core that is also used by RPi SOCs --
> requires the driver probe() to deliberately place the HW one of three
> CLKREQ# modes:
>
> (a) CLKREQ# driven by the RC unconditionally
> (b) CLKREQ# driven by the EP for ASPM L0s, L1
> (c) Bidirectional CLKREQ#, as used for L1 Substates (L1SS).
>
> The HW+driver can tell the difference between downstream devices that
> need (a) and (b), but does not know when to configure (c). Further, the
> HW may cause a CPU abort on boot if guesses wrong regarding the need for
> (c). So we introduce the boolean "brcm,enable-l1ss" property to indicate
> that (c) is desired. Setting this property only makes sense when the
> downstream device is L1SS-capable and the OS is configured to activate
> this mode (e.g. policy==superpowersave).
>
> This property is already present in the Raspian version of Linux, but the
> upstream driver implementaion that will follow adds more details and
typo, implementation
> discerns between (a) and (b).
>
> Regarding "brcm,completion-timeout-us"
>
> Our HW will cause a CPU abort if the L1SS exit time is longer than the
> PCIe transaction completion abort timeout. We've been asked to make this
> configurable, so we are introducing "brcm,completion-timeout-us".
>
> Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
What happened here? Where is the changelog?
Best regards,
Krzysztof
next prev parent reply other threads:[~2023-04-12 8:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-11 16:59 [PATCH v2 0/3] PCI: brcmstb: CLKREQ# accomodations of downstream device Jim Quinlan
2023-04-11 16:59 ` [PATCH v2 1/3] dt-bindings: PCI: brcmstb: Add two optional props Jim Quinlan
2023-04-12 8:09 ` Krzysztof Kozlowski [this message]
2023-04-12 11:49 ` Florian Fainelli
2023-04-12 11:56 ` Krzysztof Kozlowski
2023-04-12 14:14 ` Jim Quinlan
2023-04-12 15:37 ` Rob Herring
2023-04-12 16:12 ` Florian Fainelli
2023-04-18 18:35 ` Rob Herring
2023-04-21 19:07 ` Konstantin Ryabitsev
2023-04-14 20:14 ` Bjorn Helgaas
2023-04-11 16:59 ` [PATCH v2 2/3] PCI: brcmstb: CLKREQ# accomodations of downstream device Jim Quinlan
2023-04-13 14:39 ` Cyril Brulebois
2023-04-13 14:57 ` Jim Quinlan
[not found] ` <20230413200646.ddgsoqgmaae343nl@mraw.org>
2023-04-14 12:14 ` Jim Quinlan
2023-04-14 12:27 ` Florian Fainelli
2023-04-14 13:31 ` Jim Quinlan
2023-04-14 16:19 ` Cyril Brulebois
2023-04-19 14:23 ` Jim Quinlan
2023-04-19 15:57 ` Cyril Brulebois
2023-04-13 14:58 ` Florian Fainelli
2023-04-14 20:27 ` Bjorn Helgaas
2023-04-14 20:33 ` Florian Fainelli
2023-04-17 21:41 ` Bjorn Helgaas
2023-04-14 23:14 ` Jim Quinlan
2023-04-11 16:59 ` [PATCH v2 3/3] PCI: brcmstb: Set PCIe transaction completion timeout Jim Quinlan
2023-04-12 0:26 ` Cyril Brulebois
2023-04-13 18:40 ` [PATCH v2 0/3] PCI: brcmstb: CLKREQ# accomodations of downstream device Florian Fainelli
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